IL-1 gene polymorphism and marginal bone loss around dental implants

Objectives: In the two-stage implant surgery, we have found marginal bone loss around dental implants during the bone healing period,which may affect the stability of dental implants. Our study is to make clear that the relationship between the genetic polymorphisms of IL-1 gene and marginal bone loss around the implants before stageII. Methods: A total of 143 implants were placed in 59 patients. In our case-control study, the patients demonstrating marginal bone loss more than 0.5mm around implants on their panoramic radiograph at stageII surgery were designated as the 'marginal bone loss (+)' group and those not as the 'marginal bone loss (-)' group. Polymorphisms of the IL-1alpha and IL-1beta genes (IL-1A-889, IL-1B-511 and IL-1B+3954 ) were detected by restriction fragment length polymorphism using NcoI, AvaI and TaqI digestion after polymerase chain reactions. Results: The patients with IL-1B-511 II/II genotype exhibited a significantly higher occurrence of marginal bone loss than those with IL-1B-511 I/I or I/II genotype (P<0.05). Multiple logistic regressions showed the ORs of the known factors for bone loss including age, post-menopausal women, bone quality, smoking and IL-1B-511 genotype. The OR of the II/II versus the I/I+I/II of the IL-1B-511 genotype was 4.121 between the two groups and statistically significant (P<0.05). The differences between the other risk factors were non-significant(P<0.05). There was no significant difference in the distributions of the IL-1B+3954 and IL-1 A-889 genotypes between cases and controls. Conclusion: The IL-1B-511 II/II genotype in individual is associated with early marginal bone loss. This work was supported by a grant from Ph.D. Programs Foundation of Ministry of Education of China(No. B120010610059).